(1) Field of the Invention
The present invention relates to an information and electrical power transmission system and method for a vehicle. The system according to the present invention is used in a vehicle to exchange information between a controlling part in the vehicle steering device and a controlling part in the vehicle body.
(2) Description of the Related Art
A conventional device, which adopts a multiplex communication method to transmit signals from various switches provided on a vehicle steering, uses light to perform the transmission, or performs the transmission electrically through a slip ring of the vehicle. Such a device, however, transmits information only from the switches provided on the vehicle steering to the vehicle body and does not illuminate the switches provided on the steering when driving the vehicle at night, and accordingly, such a conventional device is not satisfactory.
A multiplex communication device is known which transmits electric power and information simultaneously. Such a multiplex communication device also is not satisfactory, because, when an ignition keyswitch is in an OFF state, the device does not carry out the transmission/reception of information which should be always available, such as horn information, separately from the transmission/reception of information which is not required to be always available.